The economic impacts of flood damage are a serious issue around the world. The cost of flood damage is increasing and projected to increase further as the impacts of global climate change are realized. Sea level rise as well as the greater intensity of storms inland have the potential to increase the frequency of flooding in coastal, as well as inland regions. The need for flood mitigation solutions that are quickly applied and effective against all threats witnessed in storms are needed. These devices must not only seal openings against shallow water events, but must also withstand many feet of hydrostatic pressure, and in some cases, withstand loads from hurricane force winds and moving water, and even be tamperproof against vandalism. The portable flexible sealing device of the invention has been created to fill this need.
One example of an immediate need is the protection of subway systems. Subways have ventilation (or vent) shafts which generally open at street level and are covered by rigid metal, or composite, gratings. The subway systems are equipped with pumps and drainage systems that are able to prevent flooding during typical storms. However, many cities are located near bodies of water and are becoming increasingly vulnerable to sea level rise from climate change and from tidal or storm surges. For example, in 2012, Hurricane Sandy caused billions of dollars of flood damage to New York City subway infrastructure due to the storm surge. Although there are many routes of entry for fluids to find their way into a subway system, the vent shafts have been identified as a major source. The portable flexible sealing device of the invention was created to quickly seal subway vent shafts prior to a storm to prevent flooding. Plywood sheets were installed ahead of Hurricane Sandy to prevent water from getting in through vent shafts. However, they were not effective. Several alternative approaches like raising vent shaft entrances above sea level to reduce flooding of tunnels due to storm run-off and rain water are being explored. However, these approaches require changes to the existing vent shafts covers and could prove very expensive, and are not often acceptable to a city's architectural or historical preservation needs.
In addition to coastal transit systems being at risk, climate change has also increased the intensity of storms and rainfall which cause flash flooding. Inland cities and towns all over the world have experienced flooding events which have allowed water to penetrate transit systems, commercial and industrial buildings, and other properties through ventilation, wastewater and other ducting or connecting shafts/pipes. Grated openings come in many forms and can be in numerous orientations, so sealing devices need to be adaptable in size, shape, and effects of gravity.